Febrile Neutropenia as the First Manifestation of T-Cell Large Granular Lymphocytic Leukemia.

T-cell large granular lymphocytic (T-LGL) leukemia is a rare lymphoproliferative disorder, characterized by peripheral blood and bone marrow infiltration with large granular lymphocytes (LGL), splenomegaly, cytopenias, and a frequent association with autoimmune diseases. Recurrent bacterial infections due to neutropenia are the main reason why patients come to medical attention. Despite not being a curable disease, T-LGL leukemia usually has an indolent course, with deaths mainly resulting from severe infections.